Means for cleaning well screens



Dec. 26, 1944. N. E. GUNDERSON MEANS FOR CLEANING WELL SCREENS FiledJune 15, 1942 2 Sheets-Sheet l u hO 0 a 3%. ma w a... wow. x flw wwkw m6 o o .mm

INVENTOR. Mai/.15 iw/z/flf/raan,

w MM N. E. GUNDERSON MEANS FOR GLEAfiING WELL SCREENS Filed June 15.1942 2 Sheets-Sheet 2 INVENTOR. BY Maw/.11.? fu/vam'aozr rams-someonesomen;* m rmur.- oriflce as, 1

This invention relates to well cleaners, and specifically contemplatesmeans for washing the clogged perforations of well casins reens andportions of the surrounding strata. by segregating limited areas of thescreen structure inorder Much time and study has been heretoforedirected to this question of segregating areas of" the screen, withrather limited success, it havin been found extremely diiilcult to makea device which could be readily shifted from time to time and which whenso shifted could be depended upon to accomplish segregation.

The objects of the present invention are:

To provide a simple and ellicient structure.

adapted to seat against the interior surface of a well screen andoutline an area of such screento becleanedr v s b To provide means forshifting thedevice into contact with the screen and for forcing it intosealing contact with and withdrawing it from the so I To provide meansfor compelling liquid supplied to the device and pulsated to flowalternately outward and inward through definitely restricted screenareas into and from the surrounding strata:

Toprovide means for shifting the devicelongitudinally of or laterallyaround the screen to permit positioning d contacting:

To provide a device for segregating screen areas adapted to be securedto the lower end of a we string, for shifting and'operation; v

To provide a device of the character described which is' eflective tosegregate diametricallyopposite screen areas concurrently. and operateconcurrently thereon.

The means by which the foregoing and other objects are accomplished andthe method of their accomplishment will readily be understood from v thei'ollowinl specification upon reference to the accompanying drawings, inwhich:

Fig. 1 is a vertical sectional elevation of a well screen in place in awell with'screening aggregate therearound, showing a face side of thecleaning pparatus in-elevation. 1

Hg. 2 is a fragmentary side elevation on a re- 1'18. 3 is a sectionalside elevation of the apshown in section only and thesegregating chain--bersr'et'racted from the screen.

tion taken on the nne-vv ct Fla. 4.

' Fig. 6' is a sectional-plan taken on the line' VI-Vlof Fig, 3.

The device is for, use with a well string' includ 7 ing pumpingapparatus and a discharge column In its preferred form, thedevicecomprises a pair of open face chambers, each preferably a shallow boxll, each having shallow side walls ll, endwalls II, and a bottom or.back wall is,

vertically disposed. -Conformingly secured around. the periphery of,theopen outwardlyi'aced front of each box, or

being entirely open on the top or front. The bottom wall ll of each isprovided with 8 slot of its length, These boxes are stood on end bottomtoward bottom, so that their open tops or fronts face outward, and thebottom slots are chamber, respectively, is a continuous contactingmember or gasket. of soft rubber. the outer edge-ofthis gasket in plan,alongthe pper and lower ends of the box, arcuately conforming to thecurvature of-the well screen 28 with whichit is to be used, and alongthe sides being straight to likewise conform along vertical lines. Theboxes are disposed in diametrlcallyopposed relation, with the gasketscarried-thereby, outwardly faced and with the slots in the backsvertically and inwardly Secured to the backs ll of the boxes as bywelding, a're vertically disposed pipes '21, each pipe being closedatits bottom. end and slottedv to conform to the slot in the related box,the

welding sealing the pipes to the boxes around I their respective slots.The two pipes extend upward insubstantial parallelism to and areconnected into the closed end it of a well pipe II duced scale showing amodified-form oi the device.

through which liquid, as water or oil, may be with:

drawn in usual manner, as by pump ns mach-- anlsm 3|, or be released tosurge increase flexibili y. one (or both) of thel lle may include aflexible will"!!! -4.

ll is a well column which extends tothe ground surface. the structureserving also to raise and lower or turn the device in the well. The twoP pes 21; are spacediapart to permit insertion therebetween of a pairof'spa'ced pins ll which paratusatrlghtanaleatol'ig. 1,-withthescreeneil'ect a cam member and are carried by abell extending to anddischarging above ground level.

, link I reacts to effect boxes by the cammingac on of the spaced pins.

crank lever. 35, this lever preferably including duplicate armsl-A,18-B,' disposed on opposite sides of the pipes 21 and connectedtogether by I the pins as between the pipes. The arms, fl-A,

"-13 extend laterally outward from the pins" third pin a link 38 extendsupwardly alongside one of the pipes 21 and terminates in a ball ll towhich is connected a cable 43 extending to an accessible point about thesurface of the ground. Preferably the upper end of the link 39 isguided, as by abracket 4i conveniently secured to one of the pipes 21.

The diameters of the pins 33 and sizes of the pipes 21 and projection ofthe boxes l3 and their ent material 48 are secured at their upper endson opposite sides of the. tube 29 and extend downwardly to and aresecured at their lower ends toione of the pins 33, being here shown asconnected to the upper of such pins. This connection serves not only tosecure and brace the and are connected by a third pin 31. From this thescreen area, the bowed members I! hold the boxes properly centeredtransversely to the direction in which they are to be moved apart.

The device having been positioned opposite to screenareaswhich are to becleaned the cable 4} is pulled upwardly and through the bell crank lever35, shifts the pins 33 from positions vertically, one above the other,out of such alinement, forcing the pipes 21 apart, and through thismovement forcing the gaskets. 23 into sealing contact with oppositescreen areas, thus outlining andsegregating screen areas for treatment.Thereafter the pumping mechanism may be started up to draw liquidviolently inwardly from the surrounding strata through the segregatedscreen areas and stopped or even reversed to cause discharge outwardlythrough the same areas by pressure of the liquid in the pump column ordirect reversed pumping action. This surging action is continued untilcleaning of the areas is accomplished, pumping to discharge being runfrom time to time to determine by showing of detritus in such discharge.progress of the cleaning.

lower ends of the bowed flat members or guides,

but the guides through the pin connection. serve to support the bellcrank member 3! and provide a fulcrum against which the pull of thereading apart ofthe screen is covered by each box so that full clean-While the preferred type of structure includes a two chambers which aremoved apart by the camming action, it will be understood-that one onlyof the chambers II and tubes 31 may be used, or as shown in Fig. 2, asimilar single chamber Il-A may be used, mounted on the lower end of thewell pipe "-A and the chamber be displaced laterally by action of thecamming member carried by the bell crank lever II-C, against-the wellscreen fl-A, such actionalso laterally displacing the well pipe "-A, andthe well string thereabove.

It will further be understood that the details are largely introducedfor the purpose of illustration and may be varied from except as in aclaim specifically set out.

To use the device the pump column and pumping machinery carried therebyis removed from the well and usually, though not necessarily, to eifectsaving in wear and tear on the regular pump, the pumping mechanism isreplaced by a more rugged pump better adapted to cleaning purposes.

The present device is securely coupled into the lower end of the pumpingmechanism and by means of the well column is lowered into the well untilthe boxes or chambers ll overliea section of the screen which is to becleaned, this usually being at either the extreme upper or extreme lowerend of the screen and more conveniently being at the lower end in orderthat the apparatus may be lowered until it seats and thereafter beprogressively moved upward as cleaning progresses until the usuallyknown length of screen has been covered, or until the boxes, eventuallyseating inside the solid well casing, indicate by stoppage of welldischarge that such position is reached.

In this movement into the screen area.

. operation.

ing of a horizontal belt may be accomplished by two or three shlfts,asthe case may be. After the first area belt is cleaned, the apparatus isreleased, and raised or lowered. as the case may the operationsrepeated,until the entire screen area has been'covered,,after which the deviceisremoved from the well, the regular'pumping apparatus replaced and thewell is again put in a pair of pipes secured to, opening into, andextending downwardly from, said string, each pipe respectively carryingadjacent its lower end one of said chambers and opening thereinto, topcsitlon said chambers relatively to said-' string and form passagewaysbetween said string and said chambers, said chambers being held by saidpipes with their. open faces facing outwardly toward substantiallydiametrically opposite screen areas, each of said chambers having aroundits open face a gasket having a screen contacting surface of shapeconforming to the periphery of its said screen area, and meanscarrled bysaid structure manually operable to shift said chambers apart to effectsealing contact of their respective open faces with said opposite screenareas, said means including a cammingmemberdis'posed in part betweensaid pipes, and having a laterally extending portion,

and operating linkage pivotally secured to said v cxtendingportionadjacent the outer end thereof, and extending upward along said wellstring to the ground surface.

2. .In apparatus for cleaning the screen of a well, a structureincluding a well strlng supported from the ground surface, and pumpingoperatively connected therewith, a pair of open faced chambers disposedbelow said string, a pair of pipe-like members secured to and extendingdownward from said string, each of said members respectively beingrigidly secured adjacent its lower end to one oi said chambers andopening thereinto, said members positioning said chambers below saidstring for coordinated movement therewith, said members opening intosaid string and forming passageways between said string and saidchambers, said chambers being held by said members with their open facesfacing outwardly toward substantially diametrically opposite screenareas, each of said chambers having around its open face a gasket havinga screen contacting. surface of i6 shape conforming to the periphery ofa said screen area, means carried by said structure manually operable toshift said chambers apart to eflect sealing contact of their respectiveopen faces with said opposite screen areas, said means including acammin'g member disposed in part between said members, and having alaterally extending portion, and an operating member pivotally securedto said extending portion ad- Jacent the outer end thereof, andextending upward alongsaid well string to the ground surface; andtension means oppositely secured to said chambers acting to withdrawsaid chambers from screen contact.

NORRIS E. GUNDERSON.

